Here's how to set up the qmail groups and the qmail users.
On some systems there are commands that make this easy. Solaris and Linux:
# groupadd nofiles
# useradd -g nofiles -d /var/qmail/alias alias
# useradd -g nofiles -d /var/qmail qmaild
# useradd -g nofiles -d /var/qmail qmaill
# useradd -g nofiles -d /var/qmail qmailp
# groupadd qmail
# useradd -g qmail -d /var/qmail qmailq
# useradd -g qmail -d /var/qmail qmailr
# useradd -g qmail -d /var/qmail qmails
FreeBSD 2.2:
# pw groupadd nofiles
# pw useradd alias -g nofiles -d /var/qmail/alias -s /nonexistent
# pw useradd qmaild -g nofiles -d /var/qmail -s /nonexistent
# pw useradd qmaill -g nofiles -d /var/qmail -s /nonexistent
# pw useradd qmailp -g nofiles -d /var/qmail -s /nonexistent
# pw groupadd qmail
# pw useradd qmailq -g qmail -d /var/qmail -s /nonexistent
# pw useradd qmailr -g qmail -d /var/qmail -s /nonexistent
# pw useradd qmails -g qmail -d /var/qmail -s /nonexistent
BSDI 2.0:
# addgroup nofiles
# adduser -g nofiles -H/var/qmail/alias -G,,, -s/dev/null -P'*' alias
# adduser -g nofiles -H/var/qmail -G,,, -s/dev/null -P'*' qmaild
# adduser -g nofiles -H/var/qmail -G,,, -s/dev/null -P'*' qmaill
# adduser -g nofiles -H/var/qmail -G,,, -s/dev/null -P'*' qmailp
# addgroup qmail
# adduser -g qmail -H/var/qmail -G,,, -s/dev/null -P'*' qmailq
# adduser -g qmail -H/var/qmail -G,,, -s/dev/null -P'*' qmailr
# adduser -g qmail -H/var/qmail -G,,, -s/dev/null -P'*' qmails
AIX:
# mkgroup -A nofiles
# mkuser pgrp=nofiles home=/var/qmail/alias shell=/bin/true alias
# mkuser pgrp=nofiles home=/var/qmail shell=/bin/true qmaild
# mkuser pgrp=nofiles home=/var/qmail shell=/bin/true qmaill
# mkuser pgrp=nofiles home=/var/qmail shell=/bin/true qmailp
# mkgroup -A qmail
# mkuser pgrp=qmail home=/var/qmail shell=/bin/true qmailq
# mkuser pgrp=qmail home=/var/qmail shell=/bin/true qmailr
# mkuser pgrp=qmail home=/var/qmail shell=/bin/true qmails
On other systems, you will have to edit /etc/group and /etc/passwd manually. First add two new lines to /etc/group, something like
qmail:*:2107:
nofiles:*:2108:
where 2107 and 2108 are different from the other gids in /etc/group. Next (using vipw) add six new lines to /etc/passwd, something like
alias:*:7790:2108::/var/qmail/alias:/bin/true
qmaild:*:7791:2108::/var/qmail:/bin/true
qmaill:*:7792:2108::/var/qmail:/bin/true
qmailp:*:7793:2108::/var/qmail:/bin/true
qmailq:*:7794:2107::/var/qmail:/bin/true
qmailr:*:7795:2107::/var/qmail:/bin/true
qmails:*:7796:2107::/var/qmail:/bin/true
where 7790 through 7796 are new uids, 2107 is the qmail gid, and 2108 is the nofiles gid. Make sure you use the nofiles gid for qmaild, qmaill, qmailp, and alias, and the qmail gid for qmailq, qmailr, and qmails.